Chemical examination of Ipomoea purpurea / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1908]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: Chemical examination of Ipomoea purpurea / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    of potassium hydroxide, the alcohol then removed, and the residual thick, green liquid poured into a large volume of water. The strongly alkaline liquid was extracted six times with ether, the com- bined ethereal solutions washed with water, dried with calcium chloride, and the ether removed, when a dark-colored liquid was obtained which, on cooling, solidified to a crystalline mass. This was dissolved in alcohol, the solution heated with animal charcoal, and filtered, when, on cooling, a quantity of a solid substance sepa- rated, which was collected on a filter and spread on a porous plate. After being again subjected to the same process of purification, it was finally distilled under a pressure of 15 m.m , ween it was obtained as a white, silky mass. This was crystallized from ethyl acetate, from which it separated in small, lustrous leaflets, melting sharply at 74-75° C. 0-0794 gave 0-2480 CO2 and 01042 HgO. 0 = 85-2; H= 14-6 C35H7. requires 0 = 85-4; H = 14.6 per cent. The above described substance was thus identified as pentatria- contane. The alcoholic mother-liquors from the first crystallization of the pentatriacontane were concentrated and allowed to stand, when a further portion of a solid substance separated. This was collected, dried on a porous plate, and subsequently crystallized several times from a mixture of ethyl acetate and alcohol containing a little water. It was then obtained in colorless laminae, melting at 132-133° C,, and afforded the color reactions characteristic of the phytosterols. On analysis it gave the following results: 0-1912 of the air-dried substance when heated to 105° C. lost 0-0090. H,0 = 4-7 0-0682 of anhydrous substance gave 0-2094 COj and 0-0722 HjO C = 83-7; H = n-8 C27H46 O, HjO requires H2O = 4-5 per cent. CarH^gO requires C = 83 9; H = 11-9 per cent. This substance was thus identified as a phytosterol. Its optical rotatory power was determined with the following result:— 0-2336 of anhydrous substance, dissolved in 25 c.c, of chloroform, gave ttj) — 0 36° in a 2 dcm. tube, whence [a]u — 32-1°. From the character of this phytosterol it would appear probable
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